diy solar

diy solar

Where there is smoke, there is Fire

I’m sitting at my computer last night when I smell a strong odor, something like nail polish remover. I call for my wife to see if she is working on something that might cause this. She says no, but that she also notices a strong odor near my desk.

Not far from my desk is my latest solar project. Could that be the problem? I open my plastic battery box and see smoke! I’m stunned. My LiFePO4 batteries, charged at 0.1C, have been top balanced a few days ago, but have not yet been connected to anything. How can this happen?

As fast as possible, I move the battery box out to the patio as the house is filling up with smoke. I expect flames to erupt at any moment, but no flames appeared, just lots and lots of smoke.

Once the battery box was on the patio, I removed the batteries from the box and put the now heavily smoking battery in the middle of my yard, just in case. I could see some fluid in the bottom of the battery box.

Questions:

What the hell just happened?

How is it that I and only I seem to have these types of issues and I only have a few batteries? (I would think that Will, Lithium Solar and others, who test batteries and have lots of different ones laying around, would have also experienced something similar at least once.)

What should I do next? (I am now honestly afraid of this technology. What if I had not caught it early? What if I was sleeping or out for the day and this happened? What if I was out and my wife was home when the smoke started? What if, instead of a battery box with wheels, they were mounted in a rack or some other fixed location, like in my basement, etc. or worse, an RV, etc. I would rather lose money on my batteries than lose my house or my life.)

The batteries in question are sold by Eco-Worthy and are the 150 Ah version with a blue label. I cannot recommend this product to anyone. With one battery initially DOA and this issue, I don’t believe this company has poor quality control. I believe that they have NO quality control.

Now I have a hazmat issue to fix as well.

Although the nuclear option... if you post that picture on amazon (assuming you bought it there) they will reach out to you quick, like immediately....
 
Sorry for your troubles. I’m curious how much this battery cost?

Trying to better understand the cost/quality/safety tradeoffs of various batteries. With Battle Born 100 amp hour at the top being about $800 and seemingly issue free for the great majority of customers for 10 years.

Umm victron and relion are over $1200 for 100ah.
 
The charge is auto 12v and 24v. You can see what mode the charger is in and it was correct.
What are you using for a charger? If it had absorption then that is the culprit. Does the charger have a LFP charging profile?
 
It sounds like there was an internal short in one of the cells. Perhaps unsuitable wires/connections were used in an effort to save money and one took a while to fail. Considering the batteries were in storage, this doesn't sound like user error. Give the OP a break.
 
can eco worthy be connected in series?
Yes, at least according to advertised specs, up to four in series:
 
What if one of the two paralleled batteries was highly discharged and the other fully charged and then put in parallel.

The fully charged battery will charge the highly discharged battery. The number of amps will be directly determined by the internal resistance of the two batteries.

Many battery available today have an internal resistance that is low enough that the high number of amperes (amps) will result in some degree of damage to one battery or the other.

Lower internal resistance will result in higher amps. Higher internal resistance will result in lower amps.

Hope this helps, happy to try to address any follow up questions.
 
Two batteries wired in series, connected to two other batteries wired in series
So with four batteries in series you were setting this up to be a 48v system?

It seems likely that the damage occurred the last time you charged it.
 
One of the insidious failure modes of lithium batteries is being over-discharged. If you discharge a cell below 2V, the copper current collector(s) start dissolving in the electrolyte. The copper can then plate out later when the battery is charged, and possibly form an internal short. If the battery is charged when the short happens, up it goes.

It's also possible that a BMS component failed. The "disconnect" MOSFET needs to withstand the voltage rating of the entire pack which is why some batteries can't be put in series, and some can only be put in series up to say 40-60V. Depends on the MOSFET rating. MOSFETs usually die short circuit, which means you have no protection any more and the pack can then be easily overcharged or over-discharged, leading to the failure mode above.

Certainly there's a strong argument for only buying good quality LiFePO4 batteries. This is not an area where shortcuts are well tolerated, and there are a TON of power tool batteries around with very very cheaply designed internals (I've seen enough to be concerned). My neighbour's had one of his power tool packs catch fire in the middle of the night. Kinda scary!
 
I wanted an early warning so I added these two to the hardwire of the whole house. One is a heat detector and the other is a combination photo/ionizing detector. I got these and 14/3(3+ground) Romex at Lowe’s.
Since there’s no internal combustion engine in the garage I’m not worried about false alarms. It is sensitive, 7 feet below I was heat shrinking 32 balance leads with an heat gun and I guess the adhesive lined tubing emitted some fumes I couldn’t smell. Well, every cat in the house thought the world was ending. Yah, the system works. B03C5128-B171-4443-BA60-96F2ADA80304.jpeg
 
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